In the pressure regulators used in such transmissions there occurs a temperature-dependent shift of the performance characteristic curve which, unless compensated for, has an adverse effect on gear engagement. To compensate for this characteristic curve shift in the control system, according to the prior art the temperature is measured. To do this the temperature sensors present in the electronic modules of the transmission can be used, for example the temperature sensors of the pressure sensors or the LTCC (Low Temperature Cofired Ceramic) elements. The temperature measured by these sensors is disadvantageously affected by a district time lag relative to the actual transmission oil temperature, so it is necessary to have a separate temperature sensor at a suitable point.
For that reason it has been proposed to collect return oil from the transmission in a sump and pass it through an opening around a temperature sensor. This design has the disadvantage that at low temperatures it is not certain that enough oil will collect in the sump.